Holocene dynamic of the East European forest-steppe: climate, human and fire impact

一条广阔的森林草原交错带横跨欧洲，从喀尔巴西安一直延伸到乌拉尔山脉。这种由气候决定的林区和开阔草原景观的组合适应了高度的植物多样性，这一点受到日益增加的农业活动的威胁。森林草原带以黑钙土的存在为特征，因此是世界上最重要的种植区之一。自旧石器时代以来，该地区被人类积极利用，导致大片地区转变为人为景观。到目前为止，由于现有古数据的数量和分辨率不足，该地区的自然历史在很大程度上是未知的。该项目的主要目标是重建东欧森林草原交错带在气候变化、火灾和人类影响下的全新世植被历史。选定的研究区域位于第聂伯河和顿河之间，位于交错带的中心地带，其植被组成对温度、降水和人类影响的任何变化都非常敏感。游牧民族和农业社会的各种考古文化记录了早期人类的影响。从三个关键地区采集的孢粉档案，沿着纬度梯度，从北部相邻的森林到南部的草原，研究了全新世森林草原的动态。对于可靠的年龄深度模型，档案将通过AMS-放射性碳法使用已确定的陆地植物遗骸来确定年代。将分析档案的岩性、花粉、非花粉孢粉形态、大型遗迹和木炭，从百年到十年的分辨率。根据这些数据，将重建区域和当地的植被组成、森林覆盖、气候、农业、森林砍伐、火灾历史、侵蚀和牧场。作为该项目的结果，将建立东欧森林草原全新世植被时空变化图。该项目的成果将为东欧森林草原的形成及其植被组成在全新世期间的变化、其对主要气候变化的反应和人类影响、其向现代农业景观转化的时间等重要古生态问题提供答案。澄清这些问题对于制定整个区域的可持续管理战略十分重要。

An extensive forest-steppe ecotone crosses Europe from the Carpathian to the Ural Mountains. This climatically determined combination of the forested areas with open steppe landscapes accomodates a high plant diversity, which is threatened by increasing agricultural activities. The forest-steppe zone is characterized by the presence of the chernozem soils and therefore represents one of the most important cultivation areas in the world. Since Paleolithic the region is actively used by humans leading to a transformation of the large areas to anthropogenic landscapes. Hitherto, the natural history of the zone is largely unknown as the number and resolution of existing palaeo-data are insufficient. The main goal of this project is to reconstruct the Holocene vegetation history of the East European forest-steppe ecotone under climatic changes, fire, and human impact. The selected study area between the Dnepr and the Don is situated in the heart of the ecotone with a vegetation composition very sensitive to any changes in temperature, precipitation, and human impact. Early human influence is documented by various archaeological cultures of nomads and agricultural societies. The Holocene forest-steppe dynamic will be studied on palynological archives taken from three key regions along a latitudinal gradient crossing the whole ecotone from the adjacent forests in the north to the steppes in the south. For robust age-depth models, the archives will be dated by the AMS-radiocarbon method using determined remains from terrestrial plants. The archives will be analysed for lithology, pollen, non-pollen palynomorphs, macroremains and charcoals in centennial to decennial resolution. Based on these data, regional and local vegetation composition, forest-cover, climate, agriculture, deforestation, fire history, erosion and pasture will be reconstructed. As a result of the project, maps of the Holocene vegetation change of the East European forest-steppe through space and time will be constructed.The results of the project will provide an answer to important palaeoecological problems such as the formation of the East European forest-steppe and the change of its vegetation composition during the Holocene, its reaction to the major climatic changes and anthropogenic impact, a timing of its transformation to the modern agricultural landscapes. Clarification of such questions is important for the development of the sustainable management strategies of the entire zone.